header{
    background: linear-gradient(to bottom right , #fafafa, #e9ecef); /* 标准的语法 */
}
.header{
    height:60px;
}
.headerSpan{
    line-height:60px;
    font-size:16px;
    font-weight:400;
    color:#666;
    padding-left:20px;
}
.headerImage{
    width:60px;
    height:60px;
    float:left
}
.headerBtn{
    display:block;
    float:right;
    margin-top:10px;
}